JPS5946105A - Method and device for removing solid from liquid containing suspended solid - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for removing solids from a liquid containing suspended solids. In particular, the method and apparatus of the present invention relate to packwashing a bed of cytoplasmic filter media in a direction opposite to the flow direction of the feed cycle.

Methods and apparatus for removing suspended solids from liquids are well known. One type of method and device uses filter media such as sand, gravel, diatomaceous earth, or other materials that do not tend to float or become suspended in the absence of a fairly strong upward flow of liquid. Some use Shirotoko. However, such a filter bed material called granular filter material has a suspended solids concentration of 1/liter in the liquid to be filtered.
It has been found that above the standard of 0.00 to 200 milligrams does not necessarily filter the liquid sufficiently. Under these conditions, these filter media can become clogged and stressed relatively easily on the limited surface of the filter, thereby causing the pressure head on the filter to establish a VC more quickly. .

In particular, cytoplasmic media have been found to overcome the problems of limited surface filtration and rapid pressure head establishment in typical granular media filters, especially when suspended solids concentrations are higher than the levels described above. . In this text and in the claims, the term "cytoplasmic filtration media," is used in a broad sense and is meant to include media such as synthetic foam having a diameter that is capable of retaining suspended solids.

These similar media are also sometimes referred to as "mesh filter media." A typical synthetic foam medium, as known to those skilled in the art, is urethane foam, such as polyurethane foam. Other synthetic cytoplasmic filters can be used if such a medium is used with a liquid having a specific gravity close to that of this medium. In this way, the filter media or media is subjected to a backwash under a relatively low pressure supply cycle of liquid flow.
) can be in a floating state, rather than in a high-pressure flow, such as would be used for

There is no known reliable mechanism for removing suspended solids in methods and devices using such cytoplasmic filter media. Due to the large surface species relative to the surface species ratio of typical cytoplasmic filter media, solids suspended in the liquid to be filtered are removed from the solution at °C on the outside of the cytoplasmic media or inside the cell. It is believed that foam particles can flow through the particles with the opportunity to be removed. Typical cytoplasmic filtration media are not so densely packed that the suspended solids can easily migrate through the bed. Instead, a vortex layer on the surface forms a stripe.The relatively large gaps between the particles of the cytoplasmic filter media result in a solid removal method, whereas the filter bed is made of sand, gravel, etc. If it is made of wood, it can be applied to larger types of filter beds.

Even with all of these advantages over granular media beds, cytoplasmic media beds still present difficulties in operation.

Feed Cycle Operation In a four-piece upward flow filtration device, the solid load M, (5
(olds Loadlnp). Floating particles eventually become loaded with suspended solids or mucus, so they become unbuoyant and fall due to gravity.The heavier particles fall to the inflow line. When this happens, there is a force that causes the heavier particles to obstruct the incoming fluid flow.

Also, since they fall away from the compressed filter bed, they are no longer useful for solids removal. sometimes,
Cytoplasmic filter media particles may lose their buoyancy before their solids removal capacity is exhausted.

One of the other major problems posed by the filtration of cytoplasmic filter media is cleaning the back bed, which is clogged with floating material. As prior art, polyurethane four 2. Squeeze particles (Sc+ueellng)
There are mechanical means, also called ``pressure λj?i regeneration,'' as well as mechanical means.
2/Includes using mechanical agitation of a polyurethane foam filter bed as described in No. Also, US%
πF No. 1, / / 3.26 As stated in No.
The well-known backwash method and apparatus for atactlc polypropylene filters uses a backwash method and apparatus to separate mucilage on the surface of the material being filtered from the material itself, and to assist in the wash action. '? j L/air is used for aeration of clean bacteria. However, the patent describes air directed at the filter media in a direction parallel to the direction of inlet or backwash fluid flow of the filtration application.

In seven types of cleaning for floating filter media, such as those described in U.S. Pat. It can be rotated to loosen mud cakes and other solid objects and allow them to settle to the bottom of the tank.

Mechanical agitation is expensive and tends to spoil the filter media if the blades come in contact with the media, or they do not provide enough force to remove remaining solids unless the blades come into contact with the media. ). Air scrubbing in non-cytoplasmic filter beds (
alr 5crub) in U.S. Patent No. 3. q
ss, g/q, but generally in the direction of backwash liquid flow. Other known techniques for cleaning granular filter media include U.S. Pat.
9.9g! making the plug of the filter bed fluid by injecting an air jet at right angles to the liquid flow, as described in U.S. Patent No. λ, 33 g, 3;
Sometimes horizontal airflow jets impinging at right angles to each other are injected as described in 'I 0.

However, such techniques have apparently not been used in cytoplasmic foamy media.

A further problem with cleaning cytoplasmic filter media is that the typically buoyant filter media cannot be washed away from the filtration device, especially if the filter bed is vigorously agitated during backwashing. be. 7 Preliminary measures: Slowly run the backwash water to free the solids surrounded by the filter media and allow them to fall to the bottom of the filter container, only for the media to be forced out of the filter container. Avoid disturbing the floor. This means is described in US Patent No. '1. / 9 g, 30 /
listed in the number. However, such prior art backwash flows are not always satisfactorily vigorous enough to adequately clean the filter bed. US Patent No. 1,
Certain prior art upward flow feed cycle cytoplasmic media schemes, such as the system described in No. 052.300, do not address the problem of media particle loss during backwash.

In short, prior art methods and devices do not satisfactorily solve the problem of thoroughly backwashing cytoplasmic filter media while preventing loss of filter media during the backwash process. Furthermore, prior art devices are not designed to optimize the use of the cytoplasmic filter bed over its entire depth. In addition, the prior art does not supply and utilize filter media particles when performing a filtration action, and the filter media particles are burdened with the removed solids, so they sink from the filter bed and come off the filter bed structure. B, C.

The method and apparatus 1't of the present invention overcomes some of the disadvantages of prior art apparatus and methods by keeping the filter media separate from the solids removed from the liquid.

The method and apparatus of the present invention further provides for injecting gas at an angle of approximately /3S0 to 7g0° relative to the direction of backwash fluid flow to create a shear force that causes the deformable cytoplasmic filter media to roll and capture solids. This overcomes the problems of the prior art by promoting the release of solids and enhances solids removal. By keeping the removed solids away from the filter bed, solids are prevented from re-entering the backwashed or clean filter media. Also, by positioning the inlet line of the filtration device of the present invention above the bottom of the filtration vessel, as in Example 7 of Actual #1 of the present invention, a stationary A settling zone is provided.

These solids are kept away from the filter media so they cannot be recaptured. Instead, they are collected in a dense volume, reducing the amount of backwash fluid required and the number of wasteful solids removals.

According to the method of the present invention, the backwash liquid is allowed to flow into the cytoplasmic filter media in a direction opposite to the feed cycle flow direction such that the filter bed is disturbed, and approximately relative to the direction of the packwash liquid flow. A method is provided for washing the filter bed of a cytoplasmic filter comprising injecting a gas into the cytoplasmic filter in the direction /3S0. The method of the invention is particularly characterized in that the liquid containing suspended solids flows upwardly through a bed of cytoplasmic filter media in the feed cycle, i.e. in the solids removal mode, and the packwash fluid flows into the bed of filter media. The method and apparatus are suitable for downward facing cases.

According to the device of the present invention, there is provided a filtration vessel having an outflow line and an inflow line below the outflow line, and a filtration vessel for cytoplasmic filter media particles located within the filtration vessel between the outflow line and the inflow line. A floor is provided. In addition, this device has a holding device located above the filter bed and a separating device located below the filter bed.
It is divided into a filling chamber, a filter media chamber, and a separation chamber. The retainer retains the bed of floating cytoplasmic filter media as it moves further upward into the filtration chamber during the fluid flow of the upward feed cycle. The separation chamber supports the cytoplasmic filtration media loaded with dislodged solids falling downward during the feed cycle and backwash operations, thereby preventing the filtration (4 particles from recombining with the separated solids) and the filtration vessel. to keep them from being expelled.

According to one aspect of the apparatus of the present invention, the inlet line is located 1 fft, L above the bottom of the filtration vessel, so that the settling zone is located below the separator and the inlet line. The settling zone is relatively stationary and receives solids, such as those removed from the cytoplasmic filter media particles during the pack wash and those that have settled during the feed. The inflow line is preferably located on the underside of the separator so that even when solids-laden particles fall through a clogged, rising filter bed, the entire bed of cytoplasmic filtration media is used. It has become.

The method and apparatus of the present invention provide superior packwashing and cleaning of cytoplasmic filter media over prior art methods and apparatus; the present invention separates the filter media from trapped solids removed from vertical filter media. to avoid further re-capturing of the solid. Filter media particles are prevented from being discharged from the filtration vessel. The release of heavy particles from the filter bed is also controlled to such an extent that the heavy particles cannot fall below the inlet line, thereby enhancing the upward flow action of the filter.

Bed cranking (crack+ng) is also particularly reduced compared to a downward flow arrangement, thereby eliminating wasteful use of solids that preserve the capacity of the filter media.

Other features and advantages of the present invention will be explained in detail below based on the drawings.

7. The drawings illustrate the present invention. Apply T44. RoT1.
The apparatus 10 is shown. The filtration vessel 11 is divided into three zones; a filling zone 12;
The filtration capacity 11 is divided by i2 ft, the screen or holding device 46 and the lower screen l-x or the separating device 4.
A filter bed 18 of cytoplasmic filtration particles is created by placing a filter bed 111 between the upper screen 46 and the lower screen 48 in the filter media zone 14.

According to a preferred embodiment of the invention, the upper screen 46
and the lower screen 48, at least twice the depth of the filter bed 18 of the filter medium. This relationship is rolling during backwash (tumblr+B
) for 4.1. : It is also possible to develop an extended reaction zone (described in detail below). As mentioned above, cytoplasmic filter media particles have a specific gravity less than, or approximately equal to, the specific gravity of the liquid from which suspended solids are to be removed, or in the direction of the feed cycle, the upward flow of the liquid to be filtered. Either 1. It is designed to crawl. In the drawings, the particles are shown in suspension;
It is obtained according to the invention during the first 5 to 30 percent of the feed cycle.

Often these cytoplasmic filtration particles are called “floating filter media”
In other words, it is called a "floating filter material." The term "cytoplasmic filtration media" is defined above and is intended to refer to filtration media in which pores are provided for cells or apertures into which solids enter;
and without upward feed cycle flow action, including buoyant, floating, or floating filter beds.

The particular composition of the media filter bed 18 may include particles of uniform size and weight or particles of different size and weight, thereby creating a layered bed. Such layer formation makes it possible to gradually remove dimensional solids. Layered IN is prepared using a weighting agent such as barium sulfate (welBhtlnB a
Hents).

Cytoplasmic filter media particles can be of various synthetic or natural types as are well known in the art. For example, the synthetic particles may be chopped or otherwise discontinuous or sized as is well known in the art.
Any polyurethane particles may be used. appropriate 4699727
Particles are described, for example, in US Pat. Other suitable polyurethane foam particles have about -700 holes per about 25 mm/inch and have a particle size of about 3.7 g (about 0.72 S inch) to about 25 mm/inch. l
The particle diameter varies from 100 cm to 100 cm. It should be noted that the foam particles may be of various shapes, regular or irregular, but in any event the effective particle size is as described above.

Returning to the drawing again, it can be seen that an inflow pipe 20 with an inflow pipe valve 22 and an outflow pipe 30 with an outflow pipe valve 32 are provided. The normal feed cycle direction for the apparatus of the present invention is in the upward configuration, and when valves 22 and 32 are opened, the fluid for removing suspended solids flows upwardly to the screen 4.
8 into separation zone 16 , through filter media 18 into filter media zone 14 , into manifold 34 , and through manifold converter tube 36 into outlet line 30 . The plenum zone 12 is intended to contain excess liquid from the filter media zone 14 and also provide a zone for gas accumulation during pack washes, as will be explained later.

A further seven positions for the inflow pipes are shown as inflow pipes 28 corresponding to valves 29. Stationary separation zone 16
If it is desired to provide a flow tube 28, a flow tube 28 can be used for the incoming liquid to be freed of suspended solids. In accordance with the present invention, the preferred embodiment utilizes an inlet tube 28 for the incoming liquid containing suspended solids.

In addition, the valve 40 associated with the filtration device 11 and the rice bowl imitation
k) a vent pipe 38 with an associated valve 44; Filling drain 42, filling zone 1
Two extra filters are used when it is desired to remove the Cl liquid stream.

In operation, inlet pipe valve 29 and outlet pipe valve 32 are opened and the remaining valves are closed so that the filter media particles have a specific gravity slightly greater than the specific gravity of the liquid from which suspended solids are to be removed. When filtering media, the filter media 18 is typically placed on the bottom screen 48, even though the liquid flow is upward at 8°, much of the solids to be removed remain at the bottom of the media bed 18. It grows inside and outside of the foamy medium. As the solids to be removed continue, the upward force of the fluid flow drives the bed 18 of the filter media upward until it reaches the upper screen 48, creating a loaded layer of sludge (one oaded '1ay).
er) is formed at the bottom of the bed 18 of filter media. This event typically occurs within about S percent to 30 cents at the beginning of the supply cycle.

As shown, the filter bed 18 is connected to the upper screen 4.
After moving to the position at 6, an expanded reaction zone is provided between the outlet of the inflow tube and the bottom of the bed of filter media 18 to increase the time the fluid is in contact with the bed of filter media. Solids in the fluid also have time to come into contact and aggregate, so that they become highly deformed (and fall to the bottom of the separation zone 16 without reaching the bed 18 of filter media, thus causing the filtration device 10 This increases the effective supply cycle working period.

The load layer initially formed upstream of the bed 18 or on its lower surface also improves the removal of fine particles that reach the bed 18 at its upper location.

As the feed cycle continues, the load layer advances upward through the depth of bed 1B. If the foam particles on the surface 11 of the floor 18 become too large, they fall individually or in bulk from the bulk of the floor 18 to the lower screen 48, where they , imparts a coalescing effect to the incoming solids. Also, the bottom surface of the bed 18 is renewed as the loaded media particles have completely fallen off.

Other factors related to the filtration vessel 11 include backwashing of the filtration medium 18 when the filtration medium becomes so solid that it becomes ineffective to perform further filtration in the feed cycle direction. For this purpose, a pack wash inlet l-W2O is provided and it is connected to the manifold transfer pipe 3.
It communicates with 6.

The backwash process begins by opening the vent valve 40, then opening the valve 68 to completely drain the liquid in the filtration vessel 11 through the drain pipe 66, and then draining the backwash liquid at level i of the upper screen 46. Filter container 1
1 is satisfied. Alternatively, the filtration vessel 11 can be initially drained via the fill drain pipe 42 by opening the valve 44 or, if the fill drain pipe 42 is not provided, the liquid level in the filter vessel 11 is By draining through drain pipe 66 down to the level of upper screen 46. The backwash liquid introduced via tube 50 can be either treated liquid or untreated influent depending on the quality of the effluent. Filtration container 11
is filled with liquid to the level of the upper screen 46 and the drain valve 68 is closed, and the gas is then passed through the gas scrub tube 62 to the filtration vessel 1 directly below the lower screen 48.
1. The gas scrub pipe 62 is a gas supply
i! 764 and is controlled by gas scrub pipe valve 60. The gas that enters the filter bed 18 is effective in disturbing the filtration and loosening solids. According to a preferred embodiment, this gas flows downwardly through the manifold 34 into the bed 18 of filter media in a direction approximately 0/30 relative to the direction of flow of the packwash liquid.

Such an angular gas flow causes a great deal of agitation in the filtration 1'4, resulting in high shear forces and the filtration of the removed solids. ]1. ), the water source 1 vJ (, ε twist 1 ・ma) increases, but the increased turbulence and shear force is due to the backwash liquid flow. When gas is introduced in the range between 73s0 and /g00 with respect to the direction, it is brought about. [As seen in part 1, the gas scrubbing tube 62
is the distribution manifold 6 located just below the screen 48.
5 and having a plurality of suitable openings 67 therein to direct the gas flow in the angular relationship described above. After the introduction of gas is completed, the drain valve 68 is opened and at the same time backwash liquid is introduced via the pipe 5o by opening the valve 58, thereby allowing it to be carried away from the bed. The above-mentioned washing process may be repeated as necessary until the filter bed 18 is thoroughly cleaned.

On the preferred side of the invention, tube 62. The gas scrub and backwash flow through the manifold 34 and the downward backwash fluid flow are simultaneously used in the IIUC during gas scrubbing or agitation, or as described in the art. Valves 58 and 60 may be sequenced to allow backwash liquid to be introduced after gas scrubbing or agitation, as is well known in the art. During any pack wash operation, backwash drain tube 66 is opened by opening valve 68 and inlet valve 22 or 29 is closed depending on whether inlet tube 20 or 28 is used. An option that is particularly effective under higher solids loading conditions is for gas to be introduced through manifold 65 while liquid is being discharged from filtration volume 11. The rate of agitation and increased underflow of the liquid collected on the lower screen 48 and on the filter media 18 is the same as min MfE.
Helps remove solids in zone 16. The lower liquid velocity during simultaneous gas introduction and evacuation is further increased by partially closing the vent valve 40, increasing the pressure within the filtration vessel 11.

Holding screen 46 o 6 and min jl, jp screen 4
The dimensions of 8 will depend on the dimensions of the cytoplasmic filter media particles 18. The mesh dimensions of screens 46 and 48 are sufficient to prevent filter media particles from passing through screens 46 and 48 during either the feed cycle or backwash flow under normal production conditions. Must. Such dimensions may be selected by one of ordinary skill in the art.

Although the cytoplasmic filtration media apparatus and method including the feed cycle and puncture wash operation described above are preferred,
It can be modified and modified by a skilled worker without departing from the spirit of the invention.

[Brief explanation of drawings]

The drawing is a schematic representation of a filtration vessel apparatus using the method of the invention. 10...filtration cage (units), 11...filtration container, 12...filling zone, 14...filter material zone. 16... Separation zone, 18... Filter bed, 20... Inflow pipe. 22... Inflow pipe valve, 30... Outflow pipe, 32... Outflow pipe valve, 28... Inflow pipe, 38... Ventilation pipe, 42...
... Full drain pipe, 48 ... Upper screen, 44.
... Opening valve, 34... Manifold.

Claims (1)

[Claims] l Maintaining the pack wash liquid in the bed of the cytoplasmic filtration medium, and approximately 1/3 to the direction of the pack wash liquid! A gas is introduced into the bed of the cytoplasmic filtration media in the direction of the direction of the cytoplasmic filtration media to create an agitation flow through the filtration media and create a high shear force to enhance the separation of the removed solids. A method of backwashing a bed of cytoplasmic filtration media comprising flowing solids through the bed in a direction opposite to the feed cycle flow direction to carry solids out of the bed of cytoplasmic filtration media. (3) positioning a bed of cytoplasmic filtration media in a filtration vessel; and flowing the liquid containing suspended solids through the filter bed in the filtration vessel to precipitate the solids in the cytoplasmic filtration media, thereby removing suspended solids from the liquid. A method for removing solids from a liquid containing suspended solids, the method comprising: removing the solids from the cytoplasmic filter; and periodically backwashing the settled solids from the cytoplasmic filter. The backwash of precipitated tNi is achieved by maintaining the packwash liquid in the bed of the cytoplasmic filter, and by introducing gas into the bed of the cytoplasmic filter in a direction approximately 0/3 to the left with respect to the direction of the packwash liquid. to enhance the separation of the removed solids by creating agitation through the filter media to create high shear forces, and to flow the packwash liquid through the bed of cytoplasmic media in a direction opposite to the feed cycle flow direction. and transporting the solids from a bed of cytoplasmic filter media. 3. removing suspended solids from the liquid by positioning a bed of cytoplasmic filter media in a filtration vessel; and flowing the liquid containing suspended solids upwardly through the filter bed in the filtration vessel to precipitate the solids in the cytoplasmic filter media. from the cytoplasmic filter media by removing the backwash liquid downwardly through the filter bed and simultaneously directing the gas in the cytoplasmic filter media in a direction approximately /3SO° relative to the direction of the backwash liquid flow. A method for removing solids from a liquid containing suspended solids comprising periodically backwashing the settled solids. A filtration vessel having an upper outflow line, a filter bed holding device below the upper outflow line, a bed of cytoplasmic filter media below the holding device, and a separation screen below the bed of the cytoplasmic filter media. an apparatus for discharging the liquid containing suspended solids through the outlet pipe and upwardly through the bed of cytoplasmic filtration material; removing suspended solids from the liquid by flushing and settling the solids of the cytoplasmic filtration medium; and maintaining the liquid level in the filtration vessel above the level of the filter bed 1 retainer; Introducing a gas into the bed of cytoplasmic filtration media to disturb the filtration media and release solids, and flowing a backwash liquid downward through the bed of cytoplasmic filtration media to cytoplasmic filtrate the released solids. periodic backwashing of precipitated solids from a cytoplasmic filtration material, including causing the solids to be carried away from a bed of material. The left cytoplasmic filter material has a specific gravity lower than the specific gravity of the liquid in which solids are suspended, as set forth in any one of claims 1, 3, 3, and 3. Method. The method according to any one of claims 1, 2, 3, and 3, wherein the cytoplasmic filter material is polyurethane foam particles. 7. The gas is injected simultaneously while the backwash liquid is flowing through the bed of filter media. The method described in. g. The pressure in the filtration chamber increases during backwashing of the bed of cytoplasmic filter media, claim Ω, 3.
The method according to any one of paragraphs 7 to 9. 9. The method of claim 1, wherein the distance between the filter bed holding device and the separating screen device is at least twice the depth of the bed of cytoplasmic filter media. /θ a filtration container having an outflow pipe and an inflow pipe below the outflow pipe and above the bottom of the filtration container, and a cytoplasmic filter located in the filtration chamber between the inflow pipe and the outflow pipe; a filter bed of material particles; a retaining screen device above said filter bed in which said filter bed is retained during the flow of an upward feed cycle of liquid into said filtration chamber; The loaded cytoplasmic particles fall out,
Also retained by the separator screen device during feed cycle operations and during packwash operations to thereby receive solids, particularly solids removed from the cytoplasmic media particles during packwash operations. and a separation screen device positioned below the filter bed so as to provide a settling zone below the inlet tube. 71. The apparatus of claim 70, wherein said separation screen device is located above said inlet line. /2 a filtration vessel having an outflow line and an inflow line below the outflow line; a filter bed of cytoplasmic filter media particles located in the filter chamber between the inflow line and the outflow line; A retaining screen device above the filter bed in which the filter bed is retained during the flow of the upward feed cycle of liquid into the filter chamber and the cytoplasmic filter media particles loaded with removed solids fall out. , and a separation screen device located below said filter bed so as to be retained by the separation screen device during feed cycle operations and during packwash operations. . /36 The apparatus of claim 10 or claim 72, wherein the cytoplasmic filter material particles have a specific gravity that is less than the specific IF of the liquid in which the solids are suspended. /Hiroshi The device according to claim 70 or 72, wherein the cytoplasmic filter material particles are small pieces of polyurethane foam. /Left A filtered liquid outflow pipe al and an unfiltered liquid below the outflow pipe. a filter bed of cytoplasmic filter material particles located in the front 6c filter compartment between a filtration container having a liquid inflow pipe, the inflow pipe and the outflow pipe; 7. The retention screen device above the filter bed allows the removed solids-loaded cytoplasmic media particles to fall and during the feed cycle operation. The underside of the separation screen device 12 and the inlet tube for receiving solids retained by the separation screen device during the packwash operation, and in particular solids removed from the cytoplasmic filter media particles during the packwash operation. a separation screen device located below said filter bed and above said inlet tube to provide a settling zone for receiving filtered liquid during feed cycle operations and for backing during pack wash operations; For distributing the washer fluid, the outlet pipe is connected to the outlet tube and approximately 1/3 to the direction of packwash fluid flow during packwash action. f; positioned relative to the filter bed so as to direct the gas in the direction of agitation and create a high shear force on the cytoplasmic foam particles, thereby enhancing the separation of the removed solids. A device for removing solids from a liquid containing suspended solids, the device comprising: a gas injection device; 10. The distance between the retaining screen device and the separating screen device is at least twice the depth of the filter bed. Apparatus according to any seven of clauses 72 or 75. /7 The gas injection device is approximately /3 in the direction of the puncture wash fluid flow during the pack wash action to create agitation and create shear forces on the cytoplasmic filter media to enhance separation of the removed solids. The patent Ml' is provided near the filter bed to direct the gas in the left direction.
1. The equipment described in item 10.